Time is like a diving cylinder. It can have no air or contain eighty cubic feet of air compressed to a high pressure
Schedule a bunch of activities for your day and they don't spill out. They compress. Somehow they all fit.
Maintain an uncluttered schedule expecting space, and you get diffusion.
It's called Parkinson's law, and that is one of the reasons why deadlines are so useful.
Of course, there is a limit to how much air you can fit into a tank before it ruptures.